The invention relates to a distance-related electronic driving speed regulating system for motor vehicles.
Driving speed regulating systems of this type are known, for example, from U.S. Pat. No. 5,014,200 or from European Patent Document EP 0 501 346 B1. In the case of such driving speed regulating systems, a predetermined constant speed is always maintained during a first regulating mode until a predetermined minimal distance to a preceding vehicle has been reached or is surpassed. Starting from the reaching or surpassing of this predetermined minimal distance, a regulating of the speed takes place during a second regulating mode such that the predetermined minimal distance is maintained in the form of a distance-regulated follow-on drive.
For the programming-in of the predetermined speed, a process is known, for example, from European Patent Document EP 0 501 346 B1 as well as from VDO-Querschnitt 2, xe2x80x9cTempostat Exe2x80x9d, VDOxe2x80x94Adolf Schindling AG, Schwalback (DE), May 1979, in which the driver carries out an acceleration to a desired speed value and subsequently actuates a speed set switch in order to store the momentary speed of the vehicle as the predetermined speed. If, during the subsequent regulating mode, the driver desires an acceleration or a deceleration of the vehicle speed, this can only take place in a cumbersome manner by actuating a special speed changing switch during the regulating mode.
In the case of other non-prior art driving speed regulating systems, the preselection of the predetermined speed takes place exclusively by touching incrementing or decrementing buttons or switches, in which case the predetermined speed can be upshifted or reduced in fixed steps. In the case of extensive changes of the predetermined speed desired by the driver, this results in high operating expenditures as a result of multiple touching.
It is an object of the invention to improve a distance-related electronic driving speed regulating system of the above-mentioned type such that a flexible, fast and simple manner changing the predetermined speed is created.
This object is achieved by distance-related electronic driving speed regulating system for motor vehicles, wherein a predetermined constant speed is maintained during a first regulating mode until a predetermined minimal distance to a preceding vehicle is reached or surpassed. When this predetermined minimal distance is reached or surpassed, during a second regulating mode, the speed is regulated such that the predetermined minimal distance is maintained in the form of a distance-regulated follow-on drive. In the event of an acceleration implemented by actuating the gas pedal (acceleration in the regulating mode) in the first or the second regulating mode beyond the momentarily predetermined speed (100 km/h) to an increased actual speed (125 km/h; 105 km/h), a new speed (120 km/h, 130 km/h; 110 km/h) is predetermined by operating a set operating element as a function of the increased actual speed. The invention is characterized in that the setting of the predetermined speed can additionally be carried out by a switching operating element, which is to be operated manually in order to increment the speed in steps. In the event of an actuation of the set operating element after reaching an increased actual speed (125 km/h; 105 km/h) because of the acceleration implemented by the actuation of the gas pedal during the regulating mode, the new predetermined speed is the speed which is closest to the actual speed and which is optionally situated above or below the increased actual speed and can also be reached by the switching operating element (130 km/h or 120 km/h; 110 km/h). Each momentarily predetermined speed can be displayed to the driver by an illuminated display combined with the speed display (digital or analog speedometer). Advantageous further developments of the invention are described herein.
According to the invention, in the event of an acceleration (implemented by actuating the accelerator pedal during regulating mode) beyond the momentarily predetermined speed to an increased actual speed, a new speed is predetermined as a function of the increased actual speed when a set operating element is actuated by the driver. In the following, increased actual speed is always an actual speed which is above the momentarily predetermined speed.
The essence of the invention is the setting of the predetermined speed additionally by switching operating elements (buttons or switches), which are to be actuated manually so as to increment or decrement the speed in steps. If such a switching operating element is present, the new predetermined speed, in the event of an actuation of the set operating element after reaching an increased actual speed because of the acceleration carried out by the actuation of the accelerator pedal during the regulating mode, is the next speed which is situated above or below the increased actual speed and can also be reached by the switching operating element. Accordingly, a rounding-up or off takes place starting from the reached increased actual speed. The reason for the rounding-up or-off is, in particular, that the speeds normally which can be reached in steps can be displayed, but the speed values situated in-between can not. However, the driver should always receive a display of the just predetermined speed. Because the driving speed regulating system is distance-related, no such high demand is made on the precision of the predetermined speed. However, the driver""s information is in the foreground of the display.
The set operating element is preferably equal to the switching operating element for incrementing in steps. If, in this case, after reaching an increased actual speed because of the acceleration implemented by the actuation of the accelerator pedal during the regulating mode, the switching operating element is actuated once, it is used as the set operating element. As usual, further actuations of this switching operating element result in further incrementing the speed in steps.
However, preferably overriding all functions, an actuation of the switching operating element for incrementing should, in every case, result in an increase by at least one step.
By means of this invention, a useful combination is created between an incremental setting of the desired speed and a setting oriented according to the actual speed, for a driving speed regulating system by which the operating expenditures are reduced and the capability of reacting is increased.